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A continuous-time NTSC-to-color-difference decoder has been fabricated in a 2-/spl mu/m CMOS process. The 9-mm/sup 2/ decoder includes the chrominance IF filter, automatic gain control, timing recovery, 90/spl deg/ phase shift, demodulators, hue and saturation controls. The 90/spl deg/ phase-shift circuit is based on peak detection and is used for tuning the chrominance IF filter and demodulation of the R-Y signal. The total power dissipation is 45 mW on /spl plusmn/2.5-V supplies. All circuits are fully differential. This allows the timing-recovery outputs to achieve a differential phase of 0.1/spl deg/ over a horizontal-line interval. For a standard NTSC 1 V/sub p-p/ color-bar input, the R-Y and B-Y outputs exhibit maximum phase and gain errors of 1.1/spl deg/ and 1.5/spl deg/, respectively.

Current-mode CMOS circuits are receiving increasing attention. Current-mode CMOS multiple-valued logic circuits are interesting and may have applications in digital signal processing and computing. In this paper we review several of the current-mode CMOS multiple-valued logic (MVL) circuits that we have studied over the past decade. These circuits include a simple current threshold comparator, current-mode MVL encoders and decoders, current-mode quaternary threshold logic full adders (QFAs), current-mode MVL latches, current-mode latched QFA circuits, and current-mode analog-to-quaternary converter circuits. Each of these circuits is presented and its performance described. >

The first VLSI digital signal processor that performs both high-precision image backprojection and spatial histogram calculations at raster-scan rates as high as 30 MHz is described. Realized in 1 mu m CMOS technology, this 13.3 mm*13.3 mm chip is designed to handle images as large as 1024*1024 12 b pixels. Loadable coefficients and a unified architecture allow this IC to be used with a variety of computed-tomography scanners for image reconstructions, including fan- and parallel-beam reconstruction. This chip also computes the forward Radon transform, which is a spatial histogram, permitting it to be used for iterative reconstruction algorithms. The bit lengths in the fixed-point architecture assure 12 b reconstruction accuracy. >